meillo@1: /*
meillo@1:  * compile with: gcc -lgd -lpng -lz -ljpeg  -lm resize-gd.c
meillo@1:  * build-depends: libgd2-noxpm-dev | libgd2-dev
meillo@1:  * depends: libgd2-noxpm | libgd2-xpm
meillo@1:  *
meillo@1:  *
meillo@1:  *
meillo@1:  * http://www.libgd.org/ImageCreation
meillo@1:  * http://cpan.uwinnipeg.ca/htdocs/Image-Resize/Image/Resize.pm.html
meillo@1:  * http://netpbm.sourceforge.net/
meillo@1:  *
meillo@1:  */
meillo@0: 
meillo@0: #include <stdio.h>
meillo@0: #include <stdlib.h>  /* for atoi() */
meillo@0: #include <string.h>
meillo@1: #include <ctype.h>
meillo@0: #include "gd.h" /* Bring in the gd library functions */
meillo@0: 
meillo@0: 
meillo@0: enum {
meillo@0: 	Png,
meillo@3: 	Jpg
meillo@0: };
meillo@0: 
meillo@2: struct size {
meillo@2: 	int w;
meillo@2: 	int h;
meillo@2: };
meillo@0: 
meillo@2: 
meillo@2: void
meillo@2: usage() {
meillo@2: 	puts("\
meillo@2: usage: resize-gd <size> <imagefiles> [...]\n\
meillo@2:          (keeps aspect ratio, does not enlarge images)\n\
meillo@2:        resize-gd <width>x<height> <imagefiles> [...]\n\
meillo@2:          (resizes to that size, enlarges if needed)\n\
meillo@2: ");
meillo@2: }
meillo@2: 
meillo@2: 
meillo@2: struct size
meillo@2: calcsize(struct size opt, struct size img, int enlarge) {
meillo@2: 	struct size result;
meillo@2: 
meillo@2: 	if (opt.h <= 0) {
meillo@2: 		/* keep aspect ratio */
meillo@2: 		if (!enlarge && opt.w > img.w && opt.w > img.h) {
meillo@2: 			opt.w = (img.w > img.h) ? img.w : img.h;
meillo@2: 		}
meillo@2: 		if (img.w > img.h) {
meillo@2: 			result.w = opt.w;
meillo@2: 			result.h = opt.w * (1.0 * img.h / img.w);
meillo@2: 		} else {
meillo@2: 			result.h = opt.w;
meillo@2: 			result.w = opt.w * (1.0 * img.w / img.h);
meillo@2: 		}
meillo@2: 	} else {
meillo@2: 		result = opt;
meillo@2: 	}
meillo@2: 	return result;
meillo@2: }
meillo@2: 
meillo@2: 
meillo@2: int
meillo@2: validsize(char* sp) {
meillo@2: 	while (isdigit(*sp)) {
meillo@2: 		sp++;
meillo@2: 	}
meillo@2: 	if (*sp == 'x' && isdigit(*(sp+1))) {
meillo@2: 		sp++;
meillo@2: 		while (isdigit(*sp)) {
meillo@2: 			sp++;
meillo@2: 		}
meillo@2: 	}
meillo@2: 	if (*sp != '\0') {
meillo@2: 		return 0;
meillo@2: 	}
meillo@2: 	return 1;
meillo@2: }
meillo@2: 
meillo@2: 
meillo@2: int
meillo@2: main(int argc, char* argv[]) {
meillo@0: 	int i;
meillo@0: 	int type;
meillo@0: 	gdImagePtr im_in;
meillo@0: 	gdImagePtr im_out;
meillo@0: 	FILE* in;
meillo@0: 	FILE* out;
meillo@2: 	char* c;
meillo@2: 	struct size sizeopt, sizeimg, sizedest;
meillo@0: 
meillo@0: 	if (argc < 3) {
meillo@2: 		usage();
meillo@0: 		exit(1);
meillo@0: 	}
meillo@0: 
meillo@2: 	if (!validsize(argv[1])) {
meillo@1: 		fprintf(stderr, "Invalid form of size. Has to be <size> or <width>x<height>.\n");
meillo@2: 		usage();
meillo@1: 		exit(3);
meillo@1: 	}
meillo@1: 
meillo@2: 	/* parse width and height */
meillo@2: 	sizeopt.w = atoi(argv[1]);
meillo@2: 	c = strstr(argv[1], "x");
meillo@2: 	if (c && c[1] != '\0') {
meillo@2: 		sizeopt.h = atoi(c + 1);
meillo@1: 	} else {
meillo@2: 		sizeopt.h = -1;  /* keep aspect ratio */
meillo@1: 	}
meillo@1: 
meillo@0: 
meillo@0: 	/* process images */
meillo@0: 	for (i = 2; i < argc; i++) {
meillo@0: 		printf("processing file '%s'\n", argv[i]);
meillo@0: 
meillo@1: 		if (strcmp(argv[i]+strlen(argv[i])-4, ".png") == 0) {
meillo@0: 			type = Png;
meillo@1: 		} else if (strcmp(argv[i]+strlen(argv[i])-4, ".jpg") == 0) {
meillo@0: 			type = Jpg;
meillo@0: 		} else {
meillo@1: 			fprintf(stderr, "'%s' has unknown filetype. Filename must end with (lowercase) '.png' or '.jpg'.\n", argv[i]);
meillo@1: 			continue;
meillo@0: 		}
meillo@1: 		/* load image */
meillo@1: 		in = fopen(argv[i], "rb");
meillo@0: 
meillo@0: 		if (type == Png) {
meillo@0: 			im_in = gdImageCreateFromPng(in);
meillo@0: 		} else if (type == Jpg) {
meillo@0: 			im_in = gdImageCreateFromJpeg(in);
meillo@0: 		}
meillo@1: 		/*
meillo@1: 		if ((im_in = gdImageCreateFromPng(in)) != NULL) {
meillo@1: 			type = Png;
meillo@1: 		} else if ((im_in = gdImageCreateFromJpeg(in)) != NULL) {
meillo@1: 			type = Jpg;
meillo@1: 		} else {
meillo@1: 			fprintf(stderr, "'%s' has unknown filetype. Filename must end with (lowercase) '.png' or '.jpg'.\n", argv[i]);
meillo@1: 			continue;
meillo@1: 		}
meillo@1: 		*/
meillo@1: 
meillo@0: 		fclose(in);
meillo@0: 
meillo@2: 		/* calculate target size */
meillo@2: 		sizeimg.w = im_in->sx;
meillo@2: 		sizeimg.h = im_in->sy;
meillo@2: 		sizedest = calcsize(sizeopt, sizeimg, 0);
meillo@1: 
meillo@1: 		/* copy-resize the image */
meillo@2: 		im_out = gdImageCreateTrueColor(sizedest.w, sizedest.h);
meillo@0: 		gdImageCopyResampled(im_out, im_in, 0, 0, 0, 0, im_out->sx, im_out->sy, im_in->sx, im_in->sy);
meillo@0: 
meillo@1: 		/* write image */
meillo@0: 		out = fopen(argv[i], "wb");
meillo@0: 		if (type == Png) {
meillo@0: 			gdImagePng(im_out, out);
meillo@0: 		} else if (type == Jpg) {
meillo@0: 			gdImageJpeg(im_out, out, -1);
meillo@0: 		}
meillo@0: 		fclose(out);
meillo@0: 
meillo@0: 		gdImageDestroy(im_in);
meillo@0: 		gdImageDestroy(im_out);
meillo@0: 	}
meillo@0: 
meillo@0: 	return 0;
meillo@0: }